Universe: What Next?

During the latter half of the 1990s, the answer to the above question became clearer to astronomers. It is thought likely that the Universe does not contain enough mass to prevent it from expanding forever.

As far as your GCSE is concerned, remember only these possible outcomes:

The Universe will expand forever, there being not enough mass for gravity to pull the galaxies together.

There is enough mass for gravity to slow down the expansion of the Universe, with galaxies gradually receeding more slowly from each other, never quite coming to a halt.

There is enough mass for gravity to overcome the expansion, with galaxies coming to a halt, then pulling together, eventually combining to form a singularity (like an almighty black hole).